Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: Hermie on October 20, 2006, 08:24:32 am

Title: Upsampling PS vs. ACR
Post by: Hermie on October 20, 2006, 08:24:32 am
Maybe something for the pixelpeeping department, but anyway:

We've probably all asked ourselves that question, where to upsample, in Photoshop or ACR? From Adobe we've always heard that both algorithms are very similar

There's an interesting post on the Adobe ACR forum where Adobe engineer Chris Cox confirms that ACR upsampling creates some artifacts that aren't there in Photoshop upsampling.

Quote from that thread:
"For ACR, Thomas chose a resampling kernel that gets good results but can result in more ringing artifacts than the bicubic family of resampling kernels"

See:
http://www.adobeforums.com/cgi-bin/webx?12...b6a869.3bc201eb (http://www.adobeforums.com/cgi-bin/webx?128@@.3bb6a869.3bc201eb)
or here on Adobe groupbrowser
http://adobe.groupbrowser.com/t155466.html (http://adobe.groupbrowser.com/t155466.html)

Hermie
Title: Upsampling PS vs. ACR
Post by: francois on October 20, 2006, 08:38:12 am
Quote
Maybe something for the pixelpeeping department, but anyway:

We've probably all asked ourselves that question, where to upsample, in Photoshop or ACR? From Adobe we've always heard that both algorithms are very similar

There's an interesting post on the Adobe ACR forum where Adobe engineer Chris Cox confirms that ACR upsampling creates some artifacts that aren't there in Photoshop upsampling.

Quote from that thread:
"For ACR, Thomas chose a resampling kernel that gets good results but can result in more ringing artifacts than the bicubic family of resampling kernels"

See:
http://www.adobeforums.com/cgi-bin/webx?12...b6a869.3bc201eb (http://www.adobeforums.com/cgi-bin/webx?128@@.3bb6a869.3bc201eb)
or here on Adobe groupbrowser
http://adobe.groupbrowser.com/t155466.html (http://adobe.groupbrowser.com/t155466.html)

Hermie
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=81317\")
Hernie,
You can see an example of this "issue" at the end of Jack Flesher's uprezzing article ([a href=\"http://www.outbackphoto.com/workflow/wf_60/essay.html]here[/url]), but it's nice to have an explanation from the Adobe engineers.